JPH02278151A - Gas purity measuring apparatus - Google Patents

Abstract

PURPOSE:To enable measurement and monitoring in real time by providing a measuring device being branched off a main very near various devices using a gas in gas pipings arranged therefor. CONSTITUTION:A gas being fed through a main 2 is introduced to a bypass pipeline 3 through a manual valve 6 to be connected to a measuring apparatus 1. Then, valves (solenoid valves) 9 and 12 are closed with a cock to let a gas to be measured flow to a pipeline toward a measuring device (gas chromatography) 16 and the gas is introduced to an exhaust port 15 through a vacuum pump 13 and a damage remover 14 to accomplish a measurement. Valves 8, 9 and 10 are closed with a cock to apply a highly pure nitrogen gas by a specified pressure from a nitrogen gas source 17 and a gas leak of the apparatus 1 can be inspected by a foaming liquid. When cleaning the pipeline, first, the valves 8 and 12 are closed with a cock to exhaust the pipeline with the pump 13 and then, the valve 12 is opened to make the nitrogen gas flow into the pipeline for a specified time by a specified pressure from the gas source 17.

Description

[Detailed Description of the Invention] [Summary] This gas purity measuring device is attached to the main line of the piping so as to be able to perform measurements in the immediate vicinity of equipment that uses gas. A bypass pipe is branched and attached via a valve,
A vacuum pump and an abatement device are connected to the bypass pipe through two ports of a flow rate adjustment valve, a first valve, and a cross pipe joint, and a second valve and two ports of a T-shaped pipe joint. A third valve, a measuring device, and a fourth valve are connected in series between the other mouth of the cruciform joint and the other mouth of the T-shaped joint; The other port is configured to be connected to a nitrogen gas source via a fifth valve.

(Industrial Application Field) The present invention relates to an apparatus for measuring the purity of various gases used in the manufacturing process of semiconductor devices.

In recent years, the development of semiconductor integrated circuits centered on silicon has
The technology that supports this is so-called wafer process technology, which is a series of processes from wafer to electrode formation.

In this wafer process, solids, liquids, gases (
Various materials (gases) are handled.

Among these materials, there are many whose purity is very difficult to regulate, or whose composition and concentration are strictly regulated, and the management of these materials is one of the important manufacturing technologies.

Gases in these materials include, for example, the material itself;
Or as a carrier gas, for plasma generation in various plasma chemical reactions, for cleaning, for example, nitrogen (N2), oxygen (02), hydrogen (H2).
There are simple gases such as , argon (Ar), and generally,
Delivered or stored in the form of a high-pressure gas.

These include gases that can cause fires, such as oxygen, and extremely dangerous gases that are explosive and flammable, such as hydrogen.

On the other hand, particularly as gaseous materials, so-called gaseous impurities, such as diborane (B, H, ), phosphine (PH3 ), special gases such as arsine (AsHz), p p b (1/
109) A minute amount of impurities is a problem.

In addition, these gaseous impurities are generally highly toxic, unstable at room temperature, and ignite when exposed to air; all of these gases are extremely harmful and dangerous.

Furthermore, new gases that do not previously exist in nature are being developed one after another, and there are still many whose properties and performance are not well understood.

Therefore, from the standpoint of safety as well as necessity arising from the manufacturing process, these gaseous materials, especially special gases, require stricter control than ever before.

In the manufacturing process, a particularly important control item is the purity of the gas.

(Prior Art) Various gaseous materials used in the manufacturing process of semiconductor devices and the like are used in small containers such as refture bottles in the laboratory stage.

However, when the production stage reaches the stage of mass production at a production factory, generally multiple cylinders are connected together or a large storage facility is set up for centralized control in a so-called gas box unit. The equipment is supplied via a piping system.

To measure the purity of gas, gas is usually first sampled from the piping system near the gas box unit into a sample bottle, and then the gas is analyzed using a method called gas chromatography, for example, in an analysis department separate from the place where the gas was sampled. It is measured using analytical equipment, etc.

In other words, measurements are often not real-time measurements, but post-processing measurements with a time delay of several days, for example.

[Problem to be solved by the invention]

As mentioned above, various gaseous materials used in the manufacturing process of semiconductor devices are centrally managed in gas box units, and the supplies to the equipment are carried out, for example, through rust-free steel piping or fluororesin-based pipes. This is done through a tube, etc.

Gas purity measurements are usually performed by collecting gas into a sample cylinder from the piping system near the gas box unit, and sometimes measurement results are only available after a delay of several days, for example. It was the current situation.

As a result, it is not possible to take appropriate measures in a timely manner immediately after an abnormality actually occurs, leading to problems such as instability of the process and, in some cases, adversely affecting yield.

The present invention provides a method for measuring and monitoring gas purity in real time by installing a gas purity measuring device branched from the main gas piping line in the immediate vicinity of various devices that use gaseous materials. It is an object.

[Means to solve the problem]

The problem mentioned above is that a bypass line is attached to the main line of the gas pipe by branching through a manual valve, and the bypass line has a flow ffl adjustment valve, a first valve, a cross pipe joint, etc. 2
A second valve is connected to the two ports of the T-shaped pipe joint, and a vacuum pump and an abatement device are connected to each other via the two ports of the T-shaped pipe joint. A third valve, a measuring device, and a fourth valve are connected to the mouth of the cross tube joint, and a nitrogen gas source is connected to the other mouth of the cross tube joint via a fifth valve. This can be achieved by a gas purity measuring device configured as follows.

[For production]

In the gas purity measuring device of the present invention, instead of the conventional gas purity measuring method in which a sample gas is sampled and a measurement result is obtained after a time delay, piping is connected to each of the various devices that use gas. A branch of the gas piping installed in the system is installed in the main pipeline very close to the equipment, so that the purity of the gas can be measured in real time.

In other words, a measurement system is constructed by connecting a measuring instrument such as a gas chromatography device with a vacuum pump, an abatement device, and a vent via multiple valves. It is possible to perform measurements as needed or intermittently in conjunction with a timer.

In addition, a vacuum pump is used to maintain negative pressure inside the gas purity measuring device to prevent it from flowing back into the main pipe, while a detoxification device is used to adsorb highly toxic and dangerous gases. , to prevent harm from occurring outside the system.

Furthermore, the high-purity, high-pressure nitrogen gas source makes it possible to check for gas leaks in the device and to clean the inside of the gas purity measuring device as needed.

In this way, when the purity of the gas deviates from the specified value, you can directly read the data on the display panel of the measuring device or the recorder, or, for example, install a buzzer or warning light on the gas purity measuring device. , abnormalities can be immediately recognized and dealt with.

〔Example〕

Figure 1 is a detailed explanatory diagram of the present invention, in which (A) is a configuration diagram, (B) is a pipeline system in operation, and (C) is a pipeline system during equipment inspection. be.

In the same figure (A), the manual valve 6 is a needle valve that is manually opened and closed, and a check valve (not shown) is attached thereto.

An electric automatic valve is used as the flow rate adjustment valve 7, and while measuring the gas distance, the inside of the pipeline on the bypass pipeline 3 side is always],
, 5×10' Pa.

Further, the five valves from the first valve 8 to the fifth valve 12 are solenoid valves, and are opened and closed by a control device (not shown) or manually input commands.

An oil rotary vacuum pump was used as the vacuum pump 13, and the inside of the pipe was able to be evacuated to a degree of vacuum of 10'' Pa (N/%).

The abatement device 14 uses activated carbon to adsorb harmful gases.

The measuring device 16 used a gas chromatography system that measures thermal conductivity, and was equipped with a display panel that allowed direct reading of the peak value of the response curve, as well as a recorder that could record a chromatogram.

A high-purity, high-pressure nitrogen gas cylinder is used as the nitrogen gas source 17, and the fifth valve 12 of the gas cylinder of the nitrogen gas source 17 is used.
A pressure reducing valve (not shown) was interposed between the two and the two, so that the pressure could be adjusted.

Furthermore, although the piping was made of rust-free steel, a flexible pipe 18 made of a fluororesin curl hose was installed in a part of the bypass pipe 3 to facilitate the installation of the gas purity measuring device 1. Using.

Then, the system from the flow rate adjustment valve 7 to the outlet of the cross pipe joint 4 is housed in a rack (not shown) to make it compact, and a bypass pipe 3 branched from the main pipe 2 via the manual valve 6 is connected. A flexible conduit 18 is interposed between the flow rate regulating valve 7 so that it can be freely attached and detached, and the cross pipe joint 4 and the vacuum pump 1 are connected to each other.
A vacuum rubber hose was used for connection between the 3 and 3, and it was also made detachable.

The same figure (B) is a diagram showing the pipeline system in operation, and the second valve 9 and the fifth valve 12 are closed to allow the gas to be measured to flow through the pipeline leading to the measuring instrument 16, and the vacuum pump 13, The gas is guided to the exhaust port 15 via the abatement device 14, and measurement can be performed while exhausting the gas to an exhaust treatment device (not shown).

On the other hand, FIG. 2C shows a pipe system when checking the airtightness of the gas purity measuring bag w1.

When checking this airtightness, close the first valve 8, second valve 9, and fourth valve 11, apply gas from the nitrogen gas source 17 at a pressure of 5 x 10'Pa, and use the foaming liquid to check for gas leaks. .

On the other hand, when cleaning the pipeline, first close the first valve 8 and the fifth valve 12, evacuate the pipeline with the vacuum pump ■3, then open the fifth valve 12, and This could be done by flowing nitrogen gas from the gas source 17 into the pipe line at a pressure of 2×10 5 Pa for 1 minute.

In this way, evaluation was performed by applying the present invention to a phosphine (PH,) gas pipe installed for an ion implantation device.

That is, phosphine, which was fed through the main pipe 2 at a pressure of 5×10 5 Pa, was guided to the bypass pipe 3 and connected to the gas purity measuring device 1, and the evaluation was performed using the pipe system shown in FIG. 2(B).

As a result, the measured values were continuously displayed on the display panel of the measuring instrument 16, and a chromagram was also drawn on the recorder.

It was also confirmed that gas concentration can be measured and gas purity can be monitored using the range of deflection of the indicator needle on the display panel, the spire value on the chromagram, or the area indicated by the chromagram.

Furthermore, it was confirmed that gas leakage from the gas purity measuring device 1 could be inspected using the pipe system shown in FIG. 3(C).

〔Effect of the invention〕

As described above, according to the gas purity measuring device of the present invention, the device can be placed in the gas piping system in the immediate vicinity of various devices that use gaseous materials, and the purity of gas can be measured in real time. It can be measured.

Therefore, compared to the conventional method, in which gas is sampled at a location far away from the equipment that uses the gas, for example, near the gas box unit, and results are obtained only with a time delay, it is not possible to take timely measures. In this way, if an abnormality occurs, it can be detected immediately, allowing prompt response, which greatly contributes to improving the efficiency of use of various devices that use gaseous materials and the quality of processes.

5 is a T-shaped pipe joint, 7 is a flow rate adjustment valve; 9 is the second valve, 11 is the fourth valve, 13 is a vacuum pump, 15 is an exhaust port, 17 is a nitrogen gas source, It is.

6 is a manual valve, 8 is the first valve, 10 is the third valve, 12 is the fifth valve, 14 is an abatement device; 16 is a measuring device, taste

[Brief explanation of drawings]

FIG. 1 is a detailed illustration of the invention. In the same figure, 1 is a gas purity measuring device, 3 is a bypass pipe, 2 is the main pipe, 4 is a cruciform joint,

Claims (1)

[Claims] A bypass pipe (3) is branched and attached to the main pipe (2) of the gas pipe via a manual valve (6), and the bypass pipe (3) is provided with a flow rate regulating valve. (7), the vacuum pump ( 13) and an abatement device (14) are installed in series, and a third valve ( 10)
, a measuring device (16), and a fourth valve (11) are connected, and a nitrogen gas source (17) is connected to the other port of the cross tube joint (4) via a fifth valve (12). A gas purity measuring device characterized by being connected.